The present invention relates to an improved process for producing solids by precipitation in a mixer to form a mixture of solid and liquid.
Various apparatuses and processes for producing solids by precipitation are known. Reactions of this type are frequently carried out in stirred vessels. Such processes are described in detail, for example, in O. Soehnel, J. Garside: Precipitation; Butterworth Heinemann, Oxford, 1992. Besides the complexity and cost of operating such processes, the relatively long residence times also prove to be disadvantageous. Furthermore, the existing possibilities for controlling such processes are inadequate.
EP-B 0 655 984 describes a process for producing solids by mixing two liquids, these liquids being fed together under high pressure into a decompression apparatus.
The decompression in mixing chambers of various designs dissipates the power introduced with the pressure and uses it for mixing. However, in this case high local temperature peaks occur and may result in damage to the product or formation of unwanted phases. Furthermore, signs of cavitation may occur in this elaborate high-pressure process and cause further damage to the product.